Steam-turbine.



No. 754,447 PATENTED MAR. 15,1904;

1 ";1. HBDLUND. STEAM TURBINE.

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UNITED STATES Iatented March 15, 1904.

PATENT OFFICE.

J OIIAN HEDLUND, OF STOOKHOLM, SWEDEN. I

STEAM-TURBINE.

SPECIFIQATION forming part of Letters Patent No. 754,447, dated March15, 1904. Application filed June 13, 1903. Serial No. 162,329. (Nomodel.)

To-all whom it may concern:

Be it known that I, PER J OHAN HEDLUND, of Stockholm, Sweden, haveinvented a new and useful Improvement in Steam-Turbines, of which thefollowing is a specification.

- The invention relates to compound elasticfluid turbines, and has forits object to increase the economy and efficiency thereof.

The working fluid is first expanded in the inlet-conduit of thewheel-casing down to a velocity which depends upon the restricted areaof the outlet of said conduit. From said outlet it passes into the wheelthrough a circumferential opening registering therewith. The walls ofthe wheel diverge inwardly from said opening, and between said walls aredisposed a series of buckets. By reason of this divergence the velocityof the entering fluid is changed to pressure, and at the same time itacts by impact on the wheel-buckets to cause rotation of the Wheel. Thefluid then passes through an opening within the wheel, near the hubthereof, and then moves radially outward, and finally escapes at thecontracted annular outlet between a second series of buckets theredisposed. The escaping fluid thus exercises a reactive eifect'inassisting the rotation of the wheeL' The exhaust then passes through aDe Laval nozzle disposed in a passage in the casing, whereby thevelocity of the efliux is converted into pressure in said passage, andfinally it escapes through the contracted annular outlet of said passageto the nextf wheel of the series, when the same cycle is repeated.

The accompanying drawing is a vertical longitudinal section of myturbine.

l is the wheel-shaft journaled in the casing 2. Upon it are disposedalternately radial inward-flow Wheels I III V, and radial outwardflowwheels II IV VI. The inward-flow wheels deliver their exhaust directlyinto the outwardflow wheels. The outward-flow wheels deliver theirexhaust to the inward-flow wheels through intermediate passages in thewheelcasing. A preferable mode of constructing and arranging the wheelsis as here shown. The end wheels V VI are provided with heads 4 5,integral with the hub 6. Between said heads is an annular partition 7which is supported by the buckets 8, interposed on one side betition 7and hub 6 is the annular opening 10.- The wheels V VI thus formpractically onewheel with a double set of buckets, into each of whichthe working fluid passes in turn, moving first radially inward the wheeland then radially outward. In constructing the remainingiwheels of theseries I omit in each case the head 5, the buckets 9 of wheel-IVconnecting the annular partition 7 of that wheel with the head 4 ofwheel V and the buckets 9 of wheel II connecting the annular partition-7of that wheel with the head 4 of wheel III. The inlet-opening of wheelsI IIIV is circumferential, and the walls of the said wheels divergeinwardly, the buckets 8 being located between said diverging walls. Theoutletopening of wheels II IV VI is circumferential, and the walls ofsaid wheels also diverge inwardly, the buckets 9 being located betweensaid diverging walls.

The casing 2 is preferably made in sections connected -in any suitablemanner, each of which contains a passage for the working fluid. Insection a is the inlet 11 for the working fluid and an annular chamber12,having a contracted outlet. 13 registering with the circumferentialinlet of wheel I. Between the walls converging to said contracted outletare guide-blades 14. In section b is an annular chamber 15, having aninlet-passage 16 registering with the outlet of wheel II and providedwith diverging walls and guide-blades 17. The outlet 18 is contractedand also provided with guide-blades 19. In section 0 is an annularchamber 20,

having an inlet-passage 21 registering with mented by reason of thecontraction of the outlet 13, and said velocity is changed into pressurein wheel I by reason of the divergence of the walls thereof. From wheelI the fluid passes by opening 10 to wheel 2, and on escaping therefromthe contracted outlet of said wheel causes an augmentation of itsvelocity. The passage 16 is substantially a De Laval nozzle, wherein, asfully explained in United States Patent No. 717,875, granted to Tore G.E. Lindmark, the said velocity is converted into pressure. The velocityis again increased before passing into wheel III, and then the cyclealready described is repeated in the successive pairs, III IV and V VI,of wheels until the fluid escapes at the final exhaust-outlet 28.

The casing 2 is preferably made in two parts bolted together, asindicated in dotted lines. In order to prevent leakage of steam frominlet to outlet outside of the'wheels, the casing-partitions areprovided with ribs 29, which enter recesses in the wheel-partitions 4cand 7, as shown.

I claim 1. An elastic-fluid turbine-wheel having two parallelcommunicating chambers each having walls diverging inwardly from acircumferential opening, and buckets disposed between said divergingwalls.

2. An elastic-fluid turbine-wheel having two parallel communicatingchambers each having walls diverging inwardly from a circumferentialopening, and buckets disposed between said diverging walls, incombination with a casing having an annular chamber provided with acontracted outlet registering with the inlet-opening of said wheel.

3. An elastic-fluid turbine-wheel having two parallel communicatingchambers each having walls diverging inwardly from a circumferentialopening and buckets disposed between said diverging walls in combinationwith a casing having an annular chamber provided with a contracted inletregistering with the outlet-opening of said wheel.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

PER J OHAN HEDLUND.

Witnesses:

WM. A. FURMAN, C. R. TAYLOR.

